Fruit and vegetable juices are natural sources of nutritious compounds such as vitamins and minerals as well as sources of tasteful flavors. Unfortunately, the high water content of juices contributes significantly to their transportation, handling, and storage costs. To alleviate these problems, juices have been concentrated or converted to solid forms for reconstitution or for use as an ingredient in other foods. However, the generally heat labile nature and high volatility of the nutritive, color, and flavor components of juices results in excessive losses at the elevated temperatures encountered during baking.
U.S. Pat. No. 1,512,731 to Washington discloses a method of making a powdered instant drink mix by subjecting a mixture of fruit juice and sugar to vacuum at low pressure. The resulting foam-like mass of bubbles is crushed to obtain a powder. A fruit flavored drink is formed by mixing the powdered drink mix with water.
U.S. Pat. No. 2,147,238 to Bruce discloses a method of treating fruit juices in order to make these juices easier to handle and store. The method comprises supersaturating fruit juice with dextrose and permitting the supersaturated solution to crystallize to a solid or substantially solid form. The resulting product may then be diluted to provide a beverage, utilized to flavor gelatine deserts, ices and the like or used in the preparation of jams or jellies.
U.S Pat. Nos. 4,610,890 and 4,707,367 to Miller et al. disclose a method of making a solid flavoring composition. The method entails forming an aqueous mixture of a sugar, a starch hydrolysate and an emulsifier, heating the mixture and then combining the aqueous mixture with an essential oil flavor in order to form a homogenous melt, extruding the homogenous melt into a cool solvent, and then drying the melt in a vacuum oven to remove surface solvent. The resulting particulate products are then used to flavor beverage and food products.
The encapsulation of essential oils and flavorings in matrices comprising sugar and starch hydrolyzates is disclosed in U.S. Pat. Nos. 3,041,180, 4,689,235, 5,009,900, 5,087,461 and 5,124,162. These solid products are flavoring agents and are either mixed with a carrier such as water or other food ingredients rather than being consumed in bite size pieces as a snack. In addition, they generally dissolve rapidly and would not provide a long lasting crispy texture which is similar to that of an expanded snack, cracker or cookie.
Fruit juice based hard candy is disclosed in U.S. Pat. No. 4,753,816. The product has a fruit solid content of about 5 to 25% and an added sugar component content of about 70 to about 95%. While these juice based products would take a considerable time to dissolve in the mouth, they do not provide the expanded texture and mastication properties of a cookie or cracker.
U.S. Pat. No. 5,264,238 discloses production of snack foods from a moldable vegetable or fruit paste using a two step drying process at temperatures of 80.degree. C. to 160.degree. C. to maintain the color and taste of the natural ingredients. Production of an expanded product having a cellular or cookie crumb-like structure is not disclosed.
U.S. Pat. No. 5,132,127 discloses the production of an extruded snack food wherein all or substantially all of the moisture is derived from the flavor source. The high moisture material may be a fruit juice or a vegetable juice. It is mixed with a farinaceous base such as a meal flour, or starch to produce a dough comprising about 25% to about 50% moisture. The dough is extruded at a barrel pressure of at least 200 psi and a temperature of at least 200.degree. F. within the barrel. The extrudate is dried and is then ultimately cooked by frying at a temperature above 220.degree. F. or by hot air puffing at a temperature of 400.degree. F. to 475.degree. F. These high temperatures would destroy or volatilize substantial amounts of the nutritive, flavor and color components of the juices.
The present invention provides a low fat snack product that may exhibit the texture of a cookie, cracker or expanded snack, but provides the flavor and color of fruit or vegetable juice. The products exhibit low hygroscopicity, long shelf life, and a long-lasting crispy mouthfeel. The method of the present invention results in a cellular or cookie crumb-like structure in a crispy snack while retaining much of the inherent flavor and color of the original juice.